Italian cyclist Marco Pantani died of a heart attack and was also found
to have brain and lung damage, according to initial reports from an autopsy
carried out here on Monday.

So I were probably wrong. The article linked above hints that his bone
marrow might have been damaged from EPO
abuse, and the medication found in his hotel room were anti-depressants
which probably couln't have killed him. Still, cerebral and pulmonary
oedema isn't normal, and some notes found in the room talked about cocaine
addiction.